ASSESSMENT OF WATER QUALITY INDEX OF TONGI CANAL, DHAKA

The categorization of river water quality is a valuable approach for documenting the present status of water quality in a river, which is necessary for the management of water pollution in monitored areas. The canals of Dhaka city, Bangladesh, are currently facing an imminent ecological collapse due to severe pollution and inadequate steps to address the issue. The main objective of this study is to classify the water quality of the Tongi canal by using three monitoring stations. In order to achieve this objective, a total of nine water samples were collected from three specific locations along the canal. These samples were then analyzed to calculate the Water Quality Index (WQI) using both the Weighted Arithmetic Method (WAM) and the Canadian Council of Ministers of Environment (CCME) method. The study assessed the following parameters: pH, Total Dissolved Solid (TDS), Temperature, Electrical Conductivity, Dissolved Oxygen, Chlorine (CL2), alkalinity, and turbidity. The research indicated that all the parameters surpassed the specified normal range in both approaches. According to the WAM approach, all three locations have a water quality index (WQI) value exceeding 100. In contrast, the CCME method yielded findings of 27.55, 22.53, and 31.37 for the relevant locations. In both approaches, all the areas had a significant level of water pollution, rendering it unsuitable for eating. This indicates that the water in the Tongi Canal has exceeded all limits due to the excessive pollution emitted by multiple industries and municipal wastewater. The Geographic Information System (GIS) was also used to highlight the difference in water parameters among these locations.